User interface method, system, and device in multitasking environment

ABSTRACT

In a user interface method, system and device in a multitasking environment, it is possible for a user to view all of a plurality of simultaneously executed applications by assigning different display areas to the plurality of applications. In the method, system and device, priorities of applications already being executed and of additional applications for which execution is requested are determined, and a display area size is determined and assigned to each application according to its priority. The system comprises a set-top box for performing the latter functions and a user terminal for transmitting a user request, while the device comprises a control unit for performing the latter functions.

CLAIM OF PRIORITY

This application is a continuation application of U.S. patentapplication Ser. No. 14/980,849, filed Dec. 28, 2015, in the U.S. Patentand Trademark Office, which is a continuation application of U.S. patentapplication Ser. No. 11/482,821, filed on Jul. 10, 2006, in the U.S.Patent and Trademark Office, now patented as U.S. Pat. No. 9,258,541,which claims the benefit of Korean Patent Application No.10-2005-0080330, filed on Aug. 30, 2005, in the Korean IntellectualProperty Office, the disclosures of which are incorporated herein byreference in their entireties.

BACKGROUND OF THE INVENTION Technical Field

The present invention relates to a user interface method, system anddevice in a multitasking environment.

Related Art

A user interface is indispensable in all devices that operate inresponse to a request from a user. The user interface has been developedto enhance user convenience. The user interface displays user-inputinformation and a corresponding operation status on a display means ofthe device so that a user can immediately view his or her selection andcorresponding results. That is, each time the user makes a specificselection, the user interface displays a corresponding screen on thedisplay means.

However, the user interface can display only one functional screen at atime. Accordingly, a partitioned screen has been used to display severalcontents. This screen, however, is a mere partitioned screen.

This conventional art is somewhat inconvenient since one functionalscreen is displayed at a time. Examples of inconvenience in amulti-function set-top box capable of simultaneously performing severalfunctions will be described. Such inconvenience is prominent inmulti-function devices. Some of the problems described below are foundin all conventional devices, not only those displaying only one screenin response to all user inputs.

Multi-function set-top boxes are realized by combining several advancedtechnologies including communications technology. Multi-function set-topboxes have several functions, including a communication function, anentertainment function, and a scheduling function, as well as broadcastor video on demand (VoD) receiving functions. These functions areassociated with various types of applications. Multi-function deviceshaving two or three functions have been developed in several fields, butno such device has as many functions as the multi-function set-top box.Multi-function set-top boxes will be widely used due to theirconvenience.

As mentioned above, multi-function set-top boxes have several functions.The multi-function set-top boxes can perform a single function, or theycan perform a plurality of functions simultaneously depending on auser=s selection. When the plurality of functions are performedsimultaneously, they may be performed independently or in correlationwith one another. Examples of the simultaneous performance of aplurality of functions using a multi-function set-top box include makinga call (e.g., a video call and a voice call) while viewing a broadcastprogram, checking a schedule while making a call, retrieving media filesto be transferred to others while making a call, and generating a doorphone signal indicating a visit by others while viewing a televisionprogram. The latter are examples of simultaneous performance of twoapplications. The multi-function set-top boxes can simultaneouslyperform three or more applications because of their multiple functions.

Multi-function set-top boxes using a conventional display method anddevice are inconvenient to users for the reasons given below.

In a conventional display method and device, one application is endedand then another application is started, or one application is displayedand then another application is displayed.

These problems lower user convenience. Accordingly, there is a need fora new display method and device which is suitable for use with amulti-function set-top box.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a user interfacemethod, system and device in a multitasking environment, which method,system and device are capable of improving user convenience in using amulti-function set-top box.

It is another object of the present invention to provide a userinterface method, system and device in a multitasking environment, themethod, system and device being capable of preventing a screen of anewly executed application from blocking screens of already executedapplications.

It is yet another object of the present invention to provide a userinterface method, system and device in a multitasking environment, themethod, system and device being capable of enabling users tosimultaneously view screens of two associated applications.

According to an aspect of the present invention, a user interface methodin a multitasking environment comprises: while at least one applicationis being executed, receiving a request to execute another application;determining priorities of the already executed application and the newlyexecuted application; determining the size of a display area for eachapplication according to the determined priorities; and displaying theapplications on the determined display areas.

The method may further comprise changing the determined sizes of thedisplay areas for the applications in response to a user input.

The newly executed application may be assigned the highest priority, thepriorities may be determined in response to a user input, and thepriorities may be determined by referring to pre-stored priorityinformation of each application.

The priority may comprise a first level in which an application isassigned 100 percent of an entire display area, a second level in whichan application is assigned a display area which is, by a predefinedsize, larger than that of other current applications that aresimultaneously executed, a third level in which an application isassigned a display area which is, by a predefined size, smaller thanthat of other current applications that are simultaneously executed, anda fourth level in which an application is not assigned a display areaand is executed in background.

The priority level assigned to each application may be changed inresponse to a user request, the change of the priority level in responseto the user request is sequentially performed from the first level tothe fourth level or from the fourth level to the first level, and thesecond priority level is assigned to the currently selected one of thesimultaneously executed applications.

According to another aspect of the present invention, a user interfacesystem in a multitasking environment comprises: a set-top box responsiveto reception of a request to execute another application while at leastone application is being executed for determining priorities of thealready executed application and the newly executed application, fordetermining the size of a display area for each application according tothe determined priorities, and for displaying the applications on thedetermined display areas; and a user terminal for transmitting a userrequest to the set-top box to control the set-top box.

The set-top box may change the determined size of the display area forthe application in response to the user request, the priorities may bedetermined in response to a user request, and the priorities may bedetermined by referring to a history of applications previously used bya user.

According to yet another aspect of the present invention, a userinterface device in a multitasking environment comprises a control unitresponsive to reception of a request to simultaneously execute anotherapplication while at least one application is being executed fordetermining priorities of the already executed application and the newlyexecuted application, for determining the size of a display area foreach application according to the determined priorities, and fordisplaying the applications on the determined display areas.

The control unit may change the determined size of the display area forthe application in response to user input, and the control unit maydetermine the highest priority for the newly executed application.

When a new phone call application is executed during the execution of atelevision reception application, the control unit may determine higherpriority for the phone call application.

The control unit may determine a higher priority for a transmittingphone call application than for a receiving phone call application.

The device may further comprise a storage unit for storing priorityinformation of each application, and the control unit may determine thepriorities of applications by referring to the priority informationstored in the storage unit.

The storage unit may further store size information of the display areadetermined according to the priorities, and the control unit maydetermine the size of the display area for each application by referringto the size information of the display area stored in the storage unit.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention, and many of the attendantadvantages thereof, will be readily apparent as the same becomes betterunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings, in which likereference symbols indicate the same or similar components, wherein:

FIG. 1 illustrates an example of a display screen of an interface;

FIG. 2 is a block diagram of a user interface device in a multitaskingenvironment according to an exemplary embodiment of the presentinvention;

FIGS. 3A, 3B, 3C, 3D and 3E illustrate display results according topriority in a user interface according to an exemplary embodiment of thepresent invention;

FIG. 4A illustrates a change in a display result when a user makes acall while viewing a television broadcast program in a user interfaceaccording to an embodiment of the present invention;

FIG. 4B illustrates a change in a display result when a user receives acall while viewing a television broadcast program in a user interfaceaccording to an embodiment of the present invention;

FIG. 4C illustrates a change in a display result when a user makes acall while viewing a television broadcast program in a user interfaceaccording to another embodiment of the present invention; and

FIG. 5 is a flowchart illustrating a user interface method in amultitasking environment according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The present invention will now be described more fully with reference tothe accompanying drawings, in which exemplary embodiments of theinvention are shown. This invention may, however, be embodied indifferent forms and should not be construed as being limited to theexemplary embodiments set forth herein. Rather, these exemplaryembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the concept of the invention to thoseskilled in the art.

FIG. 1 illustrates an example of a display screen of an interface.

In the display screen of such an interface, only a currently selectedapplication A is displayed. Thus, if a multi-function set-top box usingthe display screen of FIG. 1 executes one application while executinganother application, the screen is switched between the twoapplications. Accordingly, other applications B, C and D are blocked bya selected application A. Thus, the user cannot simultaneously view twoassociated screens when executing two associated applications. Forexample, in the case where the user checks a schedule while viewing atelevision program, a schedule screen blocks the television programscreen.

FIG. 2 is a block diagram of a user interface device in a multitaskingenvironment according to an exemplary embodiment of the presentinvention.

Referring to FIG. 2, the user interface device used in a multitaskingenvironment is represented by a multi-function set-top box 200 whichincludes a control unit 210, a storage unit 220, a communication unit230, and an external device connection unit 240.

The control unit 210 controls the storage unit 220, the communicationunit 230, and the external device connection unit 240 of themulti-function set-top box 200. In particular, when there is request toexecute another application while at least one application is executed,the control unit 210 determines the priorities of the already executedapplication and the newly executed application, determines the size of adisplay area for each application according to the determinedpriorities, and displays the application on the determined area. Thepriorities may be determined by the user or may be based on predefinedpriority information. The information about the priority and the size ofthe display area may be set as a default or by a user selection.

The storage unit 220 stores set information about the priorities and thesizes of display areas. The storage unit 220 may further store variousitems of information, including schedule information, electronic programguide (EPG) information used to receive and view broadcast programs, andcontent information. The communication unit 230 can connect to thenetwork and perform various communication functions, such as Internetservice, E-mail service, voice over Internet protocol (VoIP)-based voiceor video phone service, and data communication service such asmultimedia broadcasting content transmission.

The external device connection unit 240 is used to connect variousexternal devices to the set-top box 200. Examples of the externaldevices include external storage devices, digital cameras, MP3 players,digital versatile discs (DVDs), personal video recorders (PVRs), andcomputers. The multi-function set-top box 200 is able to recognize theexternal devices, which are connected to the multi-function set-top box200 via the external device connection unit 240, and is able to read orwrite data from or to the external devices. The multi-function set-topbox 200 may control functions of the external devices.

Meanwhile, function control by the multi-function set-top box 200 can beperformed using function keys of the multi-function set-top box 200 orfunction keys of a user terminal, the latter being a control devicecorresponding to the set-top box 200. Examples of the user terminalinclude a remote controller, a portable phone, and a personal digitalassistant (PDA).

The remote controller can connect to the multi-function set-top box 200using wireless local area communication technology, such as infraredcommunication and Bluetooth. Since the multi-function set-top box 200has a communication function, the remote controller of themulti-function set-top box 200 will be able to have a communicationterminal function, as well as a function of controlling the set-top box200. The set-top box 200 may further comprise a remote control unit (notshown) for receiving a control signal from the remote controller.

A portable phone, a PDA, and the like may be able to connect to theset-top box 200 over a communication network, and may be able to controlthe set-top box 200. Alternatively, a user terminal having both a remotecontroller function and a portable communication terminal function maybe used, or a user terminal for controlling the set-top box 200 througha wired connection may be used.

As described above, upon receipt of a request to execute anotherapplication while at least one application is being executed, thecontrol unit 210 determines the sizes of display areas for the alreadyexecuted application and the newly executed application, and displayseach application on the determined area.

In the latter regard, the sizes of the display areas for theapplications may be determined in response to a request from a user.

The sizes of display areas for the applications may be determinedaccording to priority assigned to each application. The priority may beassigned in accordance with several methods.

The control unit 210 may determine the priority based on an executionorder of applications. For example, the control unit 210 may assign thehighest priority to the most recently executed application. Conversely,the control unit 210 may assign the lowest priority to the most recentlyexecuted application.

The control unit 210 may determine the priority of each application byreferring to predefined priority information. Alternatively, the controlunit 210 may determine the priority to be assigned to each applicationby collecting an application use history of a user and referring to thecollected history. For example, the control unit 210 may assign higherpriority to an application having higher use frequency and lowerpriority to an application having lower use frequency. If the usehistory of the user is used to determine the priority, user-preferredapplications can be predicted. Accordingly, the priority can beefficiently determined.

The control unit 210 may determine the size of a display area fordisplaying each application by referring to information about the sizeof the display area which is determined according to each priority. Twodifferent applications may be assigned a different-sized display areaaccording to the setting of a system even though they have the samepriority.

The two different applications may be a video call and a voice call. Thevideo call and the voice call need different display areas. While thevideo call needs to display video information received from a party, thevoice call has no video information to display since it does nottransmit video information. The video call may be assigned a largerdisplay area than that of the voice call even though the twoapplications have the same priority.

That is, while the applications have the same priority, they areassigned a different size of display area by considering features of theapplications. The priority used herein may include information fordifferentiating the size of the display area assigned to eachapplication from that of other applications.

Furthermore, a performance condition corresponding to the priority, aswell as the size of the display area, may be predefined. The informationabout the priority and the size of the display area may be stored in thestorage unit 220.

The information about the priority and the size of the display areaswill be described by way of example, in which priority has four levelsfrom the first level to the fourth level. The first level is the highestpriority level and the fourth level is the lowest priority level. Fiveapplications, such as television, scheduler, menu, video call, andhardware connection status indication applications, displayed at eachlevel will be described by way of example to assist in understanding thelevels.

The first priority level is a mode in which only one selectedapplication is displayed. In the first level, the application uses 100percent of the screen. In particular, if the application performs asingle operation, the operation status may be displayed on a fullscreen.

Each of the television application, the scheduler application, the menuapplication, the video call application, and the hardware connectionstatus indication application may be displayed on a full screen when itoperates at the first priority level.

Specifically, the television application displays a received broadcastprogram on a full screen. The scheduler application displays a year=sschedule. The menu application displays a top menu, submenus, andmovement between the menus. The video call application displays itsscreen and a party=s screen on a full screen. The hardware connectionstatus indication application displays connected hardware and, ifhardware is selected, displays a list of photographs, songs, and thelike of the selected hardware in a thumb nail form.

As described above, an executed application having the first prioritylevel is displayed on a full screen. When the application is anapplication that displays information, detailed content is displayed.That is, the application having the first priority level is assigned thewidest display area so that the greatest amount of information isdisplayed.

The second priority level is a mode in which a selected application isdisplayed together with other applications. The second level applicationis expanded to occupy about 60 percent of a full screen. Informationprovided by the second level application may be displayed in an abstractform. Screen occupation size and information abstract level may bedetermined according to the setting of a system.

Each of the television application, the scheduler application, the menuapplication, the video call application, and the hardware connectionstatus indication application may be displayed on 60 percent of the fullscreen when it operates at the second priority level.

Specifically, the television application displays a received broadcastprogram on 60 percent of the full screen. The scheduler applicationdisplays a month=s schedule. The menu application displays a top menu,submenus, and movement between the menus. The video call applicationdisplays its screen and a party=s screen. The hardware connection statusindication application displays connected hardware and, if each hardwareis selected, displays a list of photographs, songs, and the like of theselected hardware in a thumb nail form.

Other applications simultaneously executed with the second levelapplication may be displayed on a remaining screen area, which is notoccupied by the second level application, according to each setpriority.

The third priority level is a mode in which an application is displayedtogether with other applications including a selected application. Thatis, the third level application is a non-selected application that isdisplayed together with the second selected level application. The thirdlevel application may occupy 10 to 20 percent of a full screen. Thethird level application provides only essential information.

Each of the television application, the scheduler application, the menuapplication, the video call application, and the hardware connectionstatus indication application may be displayed on 10 to 20 percent ofthe full screen when it operates at the third level.

Specifically, the television application displays a received broadcastprogram on an assigned area. The scheduler application displays a day=sschedule. The menu application displays only a top menu. The video callapplication displays only a party=s screen. The hardware connectionstatus indication application displays only connected hardware.

As described above, the second level application and the third levelapplication are applications which are simultaneously executed anddisplayed. One application may be either the second level application orthe third level application depending on whether the application iscurrently selected. The currently selected application is the secondlevel application. The second level application is assigned a displayarea which is, by a predetermined size, larger than the display areaassigned to the third level application.

In this regard, the second level application may be changed to the thirdlevel application, and the third level application may be changed to thesecond level application, depending on whether the second levelapplication or the third level application is currently selected.Furthermore, screen occupation sizes assigned to the second levelapplication and the third level application may be adjusted depending onthe number of displayed applications.

The fourth priority level is a mode in which an application is executedin background and is not displayed on a screen. The fourth levelapplication may provide information to a user through an indicator, ifnecessary.

Each of the television application, the scheduler application, the menuapplication, the video call application and the hardware connectionstatus indication application may be executed at the fourth level, asfollows.

The television application does not display a received broadcast programon a screen. However, the television application may output only soundof the received broadcast program according to the setting of a system.The scheduler application notifies a user of a schedule on a set timewhen a notification function is set. The video call application operatesin a standby state. The menu application and the hardware connectionstatus indication application do not work.

Meanwhile, the priority level assigned to each of the above-statedapplications may be changed according to a user request. When theapplication receives a user request to change the priority level that isassigned to an application, the device can change the priority levelassigned to the application in response to user input. The prioritylevel may be sequentially changed from the first level to the fourthlevel or from the fourth level to the first level, or it may be changedto the priority specified by the user. When the priority is sequentiallychanged, continuous circulation is possible according to a selection.For example, if the priority assigned to an application is sequentiallychanged in an order of the first level |the second level |the thirdlevel |the fourth level, the priority may be changed to the first levelwhen the priority arrives at the fourth level. Of course, each time thepriority of each application is changed, the size of the display areaassigned to the application is changed accordingly.

A display result according to each priority will be described withreference to the accompanying drawings.

FIGS. 3A, 3B, 3C, 3D and 3E illustrate examples of a display resultaccording to priority.

FIG. 3A illustrates a display result when a first level application isexecuted. In FIG. 3A, a slant line portion indicates a display area forthe first level application. Referring to FIG. 3A, the first levelapplication is displayed on a full screen.

FIG. 3B illustrates a display result when a second level application isexecuted. In FIG. 3B, a slant line portion indicates a display area forthe second level application. Further referring to FIG. 3B, the secondlevel application is displayed on 60 percent of a full screen. Inaddition, another application is displayed on an area excluding the areaassigned to the second level application.

FIG. 3C illustrates a display result when a third level application isexecuted. In FIG. 3C, a slant line portion indicates a display area forthe third level application. Further referring to FIG. 3C, the thirdlevel application is displayed on 20 percent of a full screen. Inaddition, the third level application and other third level applicationsare uniformly assigned an area excluding the 60 percent display areaoccupied by the second level application. That is, the third levelapplications are assigned 20 percent of the full screen as a displayarea.

FIG. 3D illustrates another display result when a third levelapplication is executed. In FIG. 3D, a slant line portion indicates adisplay area for the third level application. Further referring to FIG.3D, a display result of the second level application and three thirdlevel applications is shown, unlike the display result of the secondlevel application and two third level applications in FIG. 3C.

In FIG. 3D, the second level application occupies 60 percent of a fullscreen, similar to the second level application of FIG. 3C. The thirdlevel applications of FIG. 3D are uniformly assigned a remaining 40percent of the area. As a result, the third level applications of FIG.3D are assigned 40/3, i.e., about 17 percent of the display area.

FIG. 3E illustrates another display result when a fourth levelapplication is executed. In FIG. 3E, a slant line portion indicates adisplay area for the fourth level application. The fourth levelapplication operates in background, and is not actually displayed.

When beginning to execute the third new level application during thedisplay of other applications in the form illustrated in FIG. 3C, themulti-function set-top box can change the display form to the formillustrated in FIG. 3D. Conversely, when the third level application isterminated during the display of the applications in the formillustrated in FIG. 3D, the multi-function set-top box can change thedisplay form to the form illustrated in FIG. 3C.

When beginning to execute the first level new application during thedisplay of the applications in the form shown in FIG. 3C or 3D, themulti-function set-top box may change the display form to the form shownin FIG. 3A.

That is, when beginning to execute a new application or terminating anexecuted application, the multi-function set-top box can set or changethe display form. In this case, the priority of the application isreflected in the determination of the display area assigned to theapplication and the display form of the application.

Meanwhile, the multi-function set-top box may assign a different-sizeddisplay area, depending on whether the application is executed by a useror a party. A phone call is a representative application which isexecuted by a user or a party. If the user makes a call, it means thatthe call is made by the user, and if the user receives a call, it meansthat a phone call is made by a party. The multi-function set-top box mayassign a larger display area for a phone call application making a callthan for a phone call application receiving a call.

The multi-function set-top box may determine the size of the displayarea assigned to each application according to execution of theapplication or a user selection.

For example, in the case where a user makes a call while viewing atelevision broadcast program, the set-top box can change the sizes ofthe display areas assigned to a phone call application to about 80, 20and 40 percent of the full screen to display the process of inputting aparty=s telephone number, the signaling process for connection to aparty, and the conversation process after the connection is established.

In the case where a door phone rings, indicating that there is avisitor, while a user is viewing a television broadcast program, thedevice assigns 10 percent of the full screen to notify the user ofringing. When the door phone rings, the user may desire to check thevisitor. Upon receipt of a user request to check the visitor, the devicecan expand the display area of the door phone to 60 percent of the fullscreen.

In the above-described examples, the percentages of 80, 20, 40, 10, and60 percent have been only suggested to assist in understanding thepresent invention, but do not limit the present invention. The setvalues for changing the size of the display areas according to anapplication process may be set considering features of each application.The settings may follow defaults of the system or may be set by theuser.

The priority of each application may be determined relative to otherapplications which are simultaneously executed.

The assignment of priority and the related examples have been describedto assist in understanding the present invention, and are not intendedto limit the present invention. The priority described as having thefourth levels may have two levels, three levels or five levels, etc. andthe display area may be variously sized.

Hereinafter, exemplary embodiments of the present invention will bedescribed in which a user begins to make a phone call while viewing atelevision broadcast program.

FIG. 4A illustrates a change in a display result when a user makes acall while viewing a television broadcast program.

In FIG. 4A, reference numeral 400 indicates a display form when only atelevision application is executed. In this case, a broadcast program isdisplayed on a full screen. Reference numeral 410 a indicates a displayform when a user makes a call while viewing a television program. Atelephone application occupies 80 percent of the full screen and thebroadcast program occupies the remainder of the screen.

FIG. 4B illustrates a change in a display result when a user receives aphone call while viewing a television broadcast program.

In FIG. 4B, reference numeral 420 indicates a display form when only atelevision application is executed. In this case, when there is anincoming call, the display form is changed as indicated by referencenumeral 430 b. As indicated by reference numeral 430 b, the telephoneapplication occupies 20 percent of a full screen and a broadcast programoccupies 80 percent of the full screen.

FIG. 4C illustrates a change in a display result when a user makes acall while viewing a television broadcast program according to anotherembodiment of the present invention.

Referring to FIG. 4C, no application is assigned an independent displayarea, but a newly executed application is displayed in an overlappingrelation with already executed applications. In particular, FIG. 4Cshows a change in display form when a video call application is executedwhile a television broadcast program is being viewed.

In addition, FIG. 4C shows a display area assigned to the video call,the size of which is changed as the video call proceeds. When the userexecutes only the television application, the television application isdisplayed on a full screen, as illustrated by reference numeral 440 inFIG. 4C. If a user attempts to make a video call while viewing atelevision broadcast program, the video call application is displayed on80 percent of the full screen, as indicated by reference numeral 442.When the video call is established, the video call application isdisplayed on 20 percent of the full screen, as indicated by referencenumeral 444.

If another application (e.g., a schedule check application) is executedduring the phone call, the display form is changed.

Hereinafter, the user interface method in a multitasking environmentaccording to an exemplary embodiment of the present invention will bedescribed with reference to the accompanying drawings.

FIG. 5 is a flowchart illustrating a user interface method in amultitasking environment according to an embodiment of the presentinvention.

When the device receives a request to execute another application duringthe execution of at least one application (S500), it determines thepriorities of the already executed application and the newly executedapplication (S502). When a plurality of applications are not beingexecuted, but only one application is being executed, the application isdisplayed on a full screen, which will no longer be described. Thedevice may determine the priority of each application by referring topredefined information (S502). The device determines the size of adisplay area for each application according to the determined priority(S504). The size of the display area may be determined by referring topredefined information. The device then displays each application on thedetermined area (S506).

A determination of the priority and the size of the display area may bemade according to a user selection. However, since the user selection isinconvenient, the predefined information may be typically referred to.

As described above, according to the present invention, it is possibleto display a new executed application simultaneously with display ofapplications already being executed. It is possible to provide aflexible screen to a user and naturally induce the attention of the userby differentiating the sizes of the display areas assigned to aplurality of applications according to determined priority in displayingthe applications.

While the present invention has been described as being applied to themulti-function set-top box in order to provide an understanding thepresent invention, the present invention is not limited to themulti-function set-top box. The present invention may be equally appliedto all devices that provide a display-based user interface.

With the user interface method and device in a multitasking environmentaccording to the present invention, it is possible for a user to view aplurality of applications on a screen at the same time by displaying theplurality of applications and differentiating the sizes of the displayareas, if necessary. This can improve user convenience.

While the present invention has been described with reference toexemplary embodiments thereof, it will be understood by those skilled inthe art that various changes in form and detail may be made thereinwithout departing from the scope of the present invention as defined bythe following claims.

What is claimed is:
 1. A method of controlling an apparatus including ascreen in a multitasking environment, the method comprising: based on afirst user input for executing a first application, fully displaying thefirst application on a full display area of the screen; based on asecond user input for executing a second application, displaying thesecond application on the screen, wherein the displayed secondapplication visually overlaps a portion of the displayed firstapplication; based on a third user input for the first application orthe second application, displaying the first application and the secondapplication without overlapping each other; and based on a fourth userinput for selecting one application between the first application andthe second application, displaying the selected one application on thefull display area while the unselected one application is operated inbackground and not displayed on the screen.
 2. The method according toclaim 1, the displaying the first application and the second applicationwithout overlapping each other comprises: changing a size of thedisplayed first application and maintaining a size of the displayedsecond application so as not to overlap each other on the full displayarea of the screen.
 3. The method according to claim 1, the displayingthe first application and the second application without overlappingeach other comprises: adjusting a size of the displayed firstapplication and displaying the first application, of which the size isadjusted, on a remaining display area excluding a partial display areaof the screen while the second application is displayed on the partialdisplay area.
 4. The method according to claim 1, further comprising,separately controlling each of the first application and the secondapplication while the first application and the second application aredisplayed without overlapping each other.
 5. The method according toclaim 1, further comprising: changing each of a size of the firstapplication and a size of the second application while the firstapplication and the second application are displayed without overlappingeach other.
 6. The method according to claim 1, wherein at least oneamong the first application and the second application comprises atleast one among a television application, a scheduler application, amenu application, a video call application, a hardware connection statusindication application, and a telephone application.
 7. The methodaccording to claim 1, wherein the second application is an applicationthat is used most recently among a plurality of applications.
 8. Themethod according to claim 1, further comprising: displaying an indicatorrelated to the unselected one application that is operated in thebackground and is not displayed on the screen.
 9. A display apparatus ina multitasking environment, the display apparatus comprising: a screen;a processor configured to: execute a first application and fully displaythe first application on a full display area of the screen; execute asecond application and display the second application on the screen withthe first application, wherein the displayed second application visuallyoverlaps a portion of the displayed first application; display the firstapplication and the second application without overlapping each otherbased on a user input; and select one application between the firstapplication and the second application and display the selected oneapplication on the full display area while the unselected oneapplication is operated in background and not displayed on the screen.10. The display apparatus according to claim 9, wherein the processor isfurther configured to change a size of the displayed first applicationand maintain a size of the displayed second application so as not tooverlap each other on the full display area of the screen.
 11. Thedisplay apparatus according to claim 9, wherein the processor is furtherconfigured to adjust a size of the displayed first application anddisplay the first application, of which the size is adjusted, on aremaining display area excluding a partial display area of the screenwhile the second application is displayed on the partial display area.12. The display apparatus according to claim 9, wherein the processor isfurther configured to control separately each of the first applicationand the second application while the first application and the secondapplication are displayed without overlapping each other.
 13. Thedisplay apparatus according to claim 9, wherein the processor is furtherconfigured to change each of a size of the first application and a sizeof the second application while the first application and the secondapplication are displayed without overlapping each other.
 14. Thedisplay apparatus according to claim 9, wherein the processor is furtherconfigured to display an indicator related to the unselected oneapplication that is operated in the background and is not displayed onthe screen.
 15. A non-transitory computer-readable storage mediumstoring instructions configured to cause a processor to: based on afirst user input for executing a first application, fully display thefirst application on a full display area of a screen; based on a seconduser input for executing a second application, display the secondapplication on the screen, wherein the displayed second applicationvisually overlaps a portion of the displayed first application; based ona third user input for the first application or the second application,display the first application and the second application withoutoverlapping each other; and based on a fourth user input for selectingone application between the first application and the secondapplication, display the selected one application on the full displayarea while the unselected one application is operated in background andnot displayed on the screen.
 16. The non-transitory computer-readablestorage medium according to claim 15, wherein the instructions arefurther configured to cause the processor to change a size of thedisplayed first application and maintain a size of the displayed secondapplication so as not to overlap each other on the full display area ofthe screen.
 17. The non-transitory computer-readable storage mediumaccording to claim 15, wherein the instructions are further configuredto cause the processor to adjust a size of the displayed firstapplication and display the first application, of which the size isadjusted, on a remaining display area excluding a partial display areaof the screen while the second application is displayed on the partialdisplay area.
 18. The non-transitory computer-readable storage mediumaccording to claim 15, wherein the instructions are further configuredto cause the processor to separately control each of the firstapplication and the second application while the first application andthe second application are displayed without overlapping each other. 19.The non-transitory computer-readable storage medium according to claim15, wherein the instructions are further configured to cause theprocessor to change each of a size of the first application and a sizeof the second application while the first application and the secondapplication are displayed without overlapping each other.
 20. Thenon-transitory computer-readable storage medium according to claim 15,wherein the instructions are further configured to cause the processorto display an indicator related to the unselected one application thatis operated in the background and is not displayed on the screen.